There's a Crack in Everything (S01E08)

Title: A Break in the Silence Plot: Dr. Cannerts achieves a significant advancement in his quest to develop a cure for the virus. At the same time, Katie and Jake delve into hospital surveillance footage from the outbreak day, uncovering the identity of Patient Zero. Meanwhile, Jana and Suzy devise a strategy to flee the quarantine by utilizing the city's underground tunnels. In the climax, a daring mission to retrieve the possible antidote from within the cordon encounters unforeseen complications.